John Branca is all smiles over the "Michael" biopic -- especially when it comes to Miles Teller playing ... well, him. We caught Branca in L.A. Monday and he couldn't stop hyping Miles -- calling him a great actor and basically gushing over his performance in the film, which Branca also produced. Check the clip ... he also shows love to Jaafar Jackson , who steps into the King of Pop's shoes for the role. What's wild ... you'd never guess Branca's in the middle of a messy feud with Paris